Trailer-Mounted LPG Fire Trainer
The Arkansas Fire Academy has built a trailer-mounted liquefied petroleum gas fire fighting project for use throughout the state. The trailer carries a dummy LPG tank for burning and a live LPG supply tank along with the control system and necessary equipment.
Archie Moore, chief of the Ranger LPG Fire Control School, had the idea for the system and he designed and built the control system. Shelton Riggs, assistant director of the Arkansas Fire Academy, designed and built the trailer and the rest of the equipment necessary to make the system work. Labor was provided by the fire academy staff. LP gas dealers and equipment suppliers furnished an old tank and related LP gas fittings and valves.
The goal was to provide the safest and most realistic training evolution possible. To meet this goal, a steel trailer was built to carry two LPG tanks and the control station. One of the tanks is permanently mounted on the trailer. The other tank is skid-mounted so it can be unloaded onto the ground. This is the dummy tank that is burned. Also, a “Christmas tree” is carried on the trailer and is set on the ground and burned to simulate a broken line. The trailer weighs 6300 pounds with all of the equipment aboard, but with the tanks empty. Normally, the trailer is transported with empty tanks, but it can be hauled with the supply tank half full.
Trailer construction
The trailer bed is 18 feet long and 6 feet wide. The overall size is 24 X 8 feet. The chassis is made of 2-inch steel pipe welded together with 10-gauge steel on the floor. The tandem axles are from a mobile home and were cut down to 8 feet wide. Both axles have electric brakes. The hitch is a bulldog type with a 2 5/16-inch ball.
The supply tank is a specially built 500-gallon LPG tank, complete with baffles, roll bar and saddle plates. In addition to the normal fittings on top of the tank, two 1 1/4-inch outlets, one for liquid and one for vapor, are on the bottom of the tank. These two outlets have been fitted with excess flow valves and Corkin pneumatic emergency shutoff valves. The two Corkin valves are controlled by using a breathing air cylinder (15 cu. ft.) connected to the control station through a regulator.
The burn, or dummy, tank is a standard 500-gallon LPG tank that was donated. This old tank does not contain any gas. It is filled with water through a l 1/2-inch fire hose connection on the top, which is left open to relieve pressure. There is a plug on the bottom so the tank can be drained prior to being loaded back on the trailer.
Photos by Bill Simpson, Arkonsas Fire Academy
A simulated relief valve was installed by running a 2-inch pipe inside from the bottom at one end and bending to come out at the top center of the tank. This outlet was reduced to accept a 1-inch LPG relief valve that was modified by removing the spring. The relief valve is supplied by a 1-inch LPG rubber hose connected to the control station on the trailer.
The burn tank also has 3/4-inch pipe with a globe valve on top to provide a simulated shutoff valve. This valve and piping does not contain LP gas.
Burner design
A burner was made by using a 7-foot piece of 3/4-inch schedule 80 pipe and five 1/8-inch holes were drilled in the 2-inch tubing. The tubing was welded over the 3/4-inch pipe so as to enclose the six pipe holes and have them opposite the tubing holes. Metal doughnuts were used to weld the tubing to the pipe. One end of the pipe was welded closed and the other end was fitted with a 3/8inch brass LPG fitting for a 1/4-inch LPG rubber hose that is connected to the control station. The burner was mounted lengthwise under the burn tank about 12 inches from the bottom of the tank. The 4-foot burner section was centered under the tank between the legs of the skids. The burner was attached by using U bolts, leaving the plugged end loose to allow for expansion. The holes in the exhaust tubing were turned up and slightly toward the front.
The Christmas tree is mounted on the skids of the burn tank for transport and removed after unloading. It is 5 feet tall with four sets of four arms with 1/8-inch holes every 6 inches. A 1-inch hammer union connects a 12-foot length of 1-inch pipe with a screw gate valve to the tree. This pipe is connected to the control station with 1-inch LPG rubber hose. The gate valve has several holes drilled into the gate to allow it to leak. This prevents a possible release of LPG when the valve is opened for the next evolution.
Control station
A 4-foot-high control station is mounted on the front of the trailer. A seat built on a 3 1/2-foot stand gives the operator a clear view and is high enough to discourage anyone from distracting him. A needle valve controls the burner and handles are connected via cables to operate two 1/4-turn valves at the base of the control station. One of these valves operates the vapor line from the supply tank. This line is connected to the relief valve. The other valve operates the liquid line from the supply tank and is
connected to the Christmas tree. A manifold built on the tongue of the trailer allows all the hoses to be connected easily. All connections are special LPG brass connections.
The LPG school runs a week in each location. A three-hour inside class is held Monday night with a repeat session Tuesday night. The Wednesday night burning session is repeated Thursday night. This allows a fire department to send half of its members Monday and Wednesday and the other half on Tuesday and Thursday. An average of
210 fire fighters a night can be trained with the use of less than 250 gallons of liquid propane. All the gas has been donated by local gas dealers.
The school will be held in 34 cities in Arkansas this year. Regional School Coordinator Charles Butler is in charge of the training program with Staff Instructors Huel Luna, Greg Storey and Bill Simpson working with the school.
Anyone desiring more information on the trailer can contact the Arkansas Fire Academy, P.O. Box 3048, East Camden, Ark. 71701.
